1. Field of the Invention
The present invention relates to a focus detection device, a focus detection method, and a camera including the focus detection device.
2. Discussion of the Background
There has been known a focus detection device which detects focus adjusting states, that is, defocus amounts, of a photographing lens in a plurality of focus detecting areas set in a photographing screen, divides the defocus amounts into groups based on variation in the defocus amounts, and selects the optimum group which is expected to capture a main object from these groups (see Japanese Patent Application Laid-Open (JP-A) No. 2007-199261). The contents of Japanese Patent Application Laid-Open (JP-A) No. 2007-199261 are incorporated herein by reference in their entirety.